Expansion-tank.



J R; SHANKLIN.

EXPANSION TANK.

APPLIOATION FILED JAN. 16, 1908.

920,672. Patented May 4, 1909.

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Q Q E N N .IOI-IN RICHARD SHANKLIN, OF CHARLESTON, WEST VIRGINIA.

EXPANSION-TANK.

Specification of Letters Patent.

Patented May 4, 1909.

Application filed January 16, 1908. Serial No. 411,200.

To all whom it may concern.

Be it known that I, JOHN RICHARD SHANK- LIN, a citizen of the UnitedStates, residing at Charleston, in the county of Kanawha and State ofIVest Virginia, have invented a new and useful Expansion-Tank, of whichthe following is a specification.

This invention relates to expansion tanks for hot water heating systems.

As is well known, there are two styles or characters of hot waterheating systems in use, known, respectively, as closed systems and opensystems, the two being differentiated by the fact that the formerincludes a safety valve to increase the pressure in the system, and toobviate danger of explosion when the pressure reaches the danger limit,and that the latter includes an open expan sion tank in order to preventthe generation of undue pressure in the system. The closed system has adecided advantage over the open system from the fact that greaterpressure can be secured and maintained, and thus more rapid circulationwith enhanced heating capacity, but, owing to the liability of thesafety valve to stick and thus fail to relieve pressure when the dangerpoint is reached, this system has not been adopted to any very greatextent.

It is the object of the present invention, in a novel and practicalmanner with perfect safety from explosions, to secure a greater pressurein a hot water heating system than that produced by gravity, or theweight of the water in the system,wherebymore rapid circulation willresult with a correspondingincre ase in the radiation of heat.Furthermore, to render it possible, without any change in the system, toincrease or diminish the pressure therein whereby to adapt it to meetthe requirements of any locality in which it may be installed, whethersuch locality be subj ected to extreme cold, moderate cold, or torelatively mild weather. Furthermore, to secure the above objectswithout necessitating any change in the existing arrangements of hotwater heating systems.

With the above and other objects in view, as will appear as the natureof the invention is better understood, the same consists, generallystated, in a closed steam and water tight expansion tank depending fromthe top of which is a novel form of pressure regulator or safety valvecomprising an infiuent tube sealed at its upper and lower ends andprovided at an intermediate point with a plurality of orifices, and an.efliuent tube disposed preferably concentric of the influent tube andhaving its ends open, the lower end being terminated adjacent to thelike end of the influent tube and its upper end being connected with aseparating chamber including a perforated deflecting plate. The iniiuenttube will contain a body of mercury which forms a seal for the lower endof the effluent tube, and the pressure in the system will be directlyproportionate to the resistance to lifting presented by the mercury, asbefore the water or air, or both can escape from the expansion chamber,it will be necessary for the water followed by the air in the tank tolift the column of mercury upward into the separating chamber where theair and water separate from the mercury, and the former escap-cs througha suitable overflow or escape pipe and the latter returns to the lowerend of the influent tube again to seal the effluent tube. As will beobvious, by augmenting the volume of the mercury, the pressure in thesystem can be increased, and, by decreasing its volume, the pressurewill be diminished.

As a matter of further and specific improvement, and to secure increasedpressure in the system without augmenting the volume of mercury, aliquid dividing member may be employed, in the nature of a tube, whichwill be disposed within the effluent tube and will operate to reduce itsinternal diameter and also to present an additional path of escape forthe water and mercury from the seal upward to the separating chamber. I

A further feature of the invention resides in the fact that by employinga hermetically sealed expansion tank and by disposing the outlet openingin the influent tube intermediate of its ends, there is provided acompressed air space above the level of the water in the tank, and theair thus confined will operate to check the expansion of the water untilits pressure is sufficient to lift the 1nercury from the seal to theseparating chamher. In addition, the compressed air operates to retain apressure in the system for a greater length of time than could otherwiseresult, thereby materially augmenting the circulation .of the waterthrough the system.

The invention consists further in the varione novel features ofconstruction and combi nation and novel arrangement of parts of anexpansion chamber for hot water heating systems, as will be hereinafterfully described and claimed.

In the accompanying drawings forming a part of this specification, andin which like characters of reference indicate corresponding parts,Figure 1 is a view in vertical section through an expansion chamberconstructed in accordance with the present invention. Fig. 2 is asimilar view of a slightly modified form. Fig. 3 is a plan view of adiaphragm used in connection with the apparatus.

Referring to the drawings, 1 designates the shell or body of theexpansion chamber, the bottom, and 3 the top thereof. These parts willbe made preferably of galvanized boiler iron, and the chamber as a.vhole is constructed as an ordinary domestic range boiler The bottom 2has connected with it an expansion pipe 4 that connects with the returnpipe or with the heater in the basement of the building in which thetank is installed. The top 3 is provided its center with an orificethrough which projects an interiorly threaded nipple 5 provided with aflange 6 that bears upon the outer face of the top and is held assembledtherewith by rivets 7. The nipple is engaged by a union 8 which isprovided with exterior threads for the purpose, and the upper end or"the union is reduced and exteriorly threaded and is en gaged by thelower member of a separating chamber, designated generally 10, the uppermember 11' of which is connected with the member 9 by bolts or rivets 12that pass through marginal flanges provided on the two members for thepurpose. The flanges serve to hold in position a deflecting plate ordiaphragm 13, which is constructed of a sheet of metal and is providedwith any desired number of orifices 14, three being shown in thisinstance, which are preferably equally spaced and disposed adjacent tothe walls of the chamber members or shells 9 and 11. The member 1 1 isprovided with an upstanding interiorly threaded boss 15, that is disposed centrally thereof and is engaged by an ordinary overflow pipe 16.

The neck portion of the union is interiorly threaded, and is engaged bythe upper threaded end of a tube 17, while that portion of the unionthat engages with the nipple is interiorly threaded and is engaged bythe upper threaded end of a tube 18, the lower end of which ishermetically sealed by a cap 19 held in place on the tube preferably bya threaded connection therewith. he tube 18 is provided at any desiredpoint intermediate of its ends with a plurality of circumferentiallyalined orifices 20 that serve to establish communication between theinterior of the tank and the tube. As clearly shown in Figs. 1 and 2,the tube 17 terminates short of the cap 19, and tne lower end of thetube 18 1S i'illed with a column of mercury 21,

the volume of which will depend upon thepressure it is desired tomaintain within the system.

As will. be readily understood, the air and water in the tank passthrough the outlet orifices 20 into the interior of the tube 18, whichconstitutes the latter an iniluent tube, and that the mercury, air andwater pass upward through the tube 1'7 to the separating chamber,thereby constituting the latter tube an eflluent tube, and these twotubes, in conjunction with the cap 19 and column of mercury 21,constitute the parts of a safety valve of which the mercury is thevalve.

As will be obvious, the pressure in the system may increased ordiminished by varying the volume or bulk of the mercury; but, should itbe desired to increase the pressure without adding to the mercury, thearrangement shown in Big. 2 is employed. This consists of a tube 22,which is loosely disposed within the ellluent tube 17, and has its endsoppositely beveled, in order to insure passage taercthrough. The tube issomewhat less in length than the distance between the cap 19 and thedeflecting plate, and rests upon. the former, but is out of contact withthe latter. Owing to the fact that part of the mercury, air and waterwill pass through the tube 22, this constitutes the element a liquiddividing member, and, as will be perfectly obvious, the increased resistance presented to the passage of the mercury, air and waterexteriorly and interiorly oi the tube 22 will be equivalent toincreasing the bulk of the mercury. in order to determine the level ofthe water in the tank at a glance, an ordinary glass gage 23 isemployed.

The operation oi the tank is as follows: So long as the pressure withinthe system is normal, the water in the tank will be below the outletopenings 20, but as soon as the pressure increases, the water willnaturally expand and approach the openings, but will be retarded or heldin check by the air in the tank above the water, hereb: maintaining arelatively high pressure on re system with increased heat and Should thepressure reach a circulation. point that might be dangerous, the waterwill be forced through the openings 20 and in conjunction with the airwill act upon the column oi water already within the influent tr 2e 18,and this pressure will gradually e exerted upon the mercury or safetyvalve 21, which will be forced. upward through the cilluent tube, and assoon as it enters the separating chamber, the water and air separatefrom the mercury, and the former escapes out through the openings 1a ofthe deflecting plate to the overflow pipe 16, and the latter returns tothe lower end of the influent tube, and again establishes the seal.

As will be obvious, owing to the inherent property of the mercury toremain liquid under all normal conditions, it will be positive inoperating at all times, so that any danger of excessive or dangerouspressure in the system will be positively precluded. It will also beobvious that as the mercury will not evaporate from the action of thewater or heat, its use will continue indefinitely, in fact, as long asthe expansion tank will last.

I claim 1. The combination with a closed expansion tank adapted for usein hot water heating systems, of a terminally sealed tube depending fromthe top thereof and communicating intermediate of its ends with thetank, a separating chamber supported by the tank, a second tube arrangedwithin the first named tube and communicating at its upper end with theseparating chamber and terminating short of the lower end of the outertube, and a body of mercury in the outer tube for sealing the lower endof the inner tube.

2. The combination with a closed expan sion tank adapted for use in hotwater heating systems, of a safety valve arranged therein and embodyingan influent tube having its terminals sealed and provided intermediateof its ends with outlet openings, an effluent tube arranged within thefirst-named tube and terminating short of the bottom thereof, a column.of mercury normally sealing the lower end of the eflluent tube, andmeans for varying the resistance to the lifting of the mercury, wherebyto increase or diminish the pressure in the system employing the tank.

3. The combination with a closed expansion tank adapted for use in hotwater heating systems, of a safety valve arranged therein and embodyinga in'fluent tube having its terminals sealed and provided intermediateof its ends with openings, an effluent tube arranged within thefirst-named tube and terminating short of the bottom thereof, means fordividing the column of liquid in the effluent tube, and a body ofmercury normally sealing the lower end of the last-named tube.

4. The combination with a closed expansion tank adapted for use in hotwater heating systems, of a safety valve arranged therein and embodyingan influent tube havin its terminals sealed and provided intermediate ofits ends with openings, an effluent tube arranged within the firstnamedtube and terminating short of the bottom thereof, a liquid dividing tubedisposed within the emuent tube, and a body of mercury normally sealingthe lower end of the last-named tube.

5. The combination with a closed expan sion tank adapted for use in hotwater heating systems, of a safety valve arranged therein and embodyingan influent tube having its terminals sealed and provided intermediateof its ends below the top of the chamber with outlet openings whereby toprovide a compressed air space above the level of the liquid of theexpansion tank, an effluent tube arranged within the firstnamed tube andterminating short of the bottom thereof, and a body of mercury normallysealing the lower end of the effluent tube.

6. The combination with a closed expansion tank adapted for use in hotwater heating systems, of a separating chamber carried thereby, aninfluent tube sealed at its terminals and arranged within the tank andprovided intermediate its ends with outlet openings, an efiuent tubearranged within the first-named tube and communieating at its upper endwith the separating chamber and terminating at its lower end short ofthe like end of the influent tube, and, a safety valve, consisting of abody of mercury, for sealing the lower end of the effluent tube.

7. The combination with a closed expansion tank adapted for use in hotwater heating systems, of a separating chamber carried thereby andincluding a perforated deflecting plate, an influent tube sealed at itsterminals and arranged within the tank and provided intermediate of itsends with outlet openings, an effluent tube arranged within thefirst-named tube and communi eating at its upper end with the separatingchamber beneath the deflecting plate and terminating at its lower endshort of the like end of the influent tube, and a safety valve,consisting of a column of mercury, for sealing the lower end of theeffluent tube.

8. The combination with a closed expan sion tank adapted for use in hotwater heating systems, of a safety valve arranged therein and embodyingan influent tube having its terminals sealed and provided intermediateof its ends with openings, an effluent tube arranged within thefirstnamed tube and terminating short of the bottom thereof, a liquiddividing tube disposed within the effluent tube and having its terminalsoppositely beveled, and a body of mercury normally sealing the lower endof the last-named tube.

9. The combination with a closed expansion tank adapted for use in hotwater heating systems, of a safety valve arranged therein and.comprising a terminally sealed tube depending from the top of the tankand provided intermediate of its ends with openings, that portion of thetank below the openings constituting a water chamber and that portionabove the openings conas my own, I have hereto aifixed my signastitutlnga compressed a1r chamber, a second ture in the presence or" twoWitnesses. tube arranged wlthln the first-named tube and terminatingshort of the bottom of the JOHN RICHARD SHANKLIN 5 latter, and a body ofmercury for sealing Witnesses:

the lower end of the second tube. GEORGE D. HOFFMAN,

In testimony that I claim the foregoing FRANK S. APPLEMAN.

